Reverse shoulder arthroplasty for scapular glenoid deformities: a retrospective cohort study

BACKGROUND: Reverse shoulder arthroplasty (RSA) is increasingly becoming a standard surgical treatment for shoulder joint pathologies. As we know, lateralization of the scapular component of the shoulder endoprosthesis plays an important role in deformities of the glenoid process of the scapula. A number of methods are used to lateralize the scapular component, one of which is the use of a custom-made metal augment. We present the results of treating patients who underwent standard reverse shoulder arthroplasty without glenoid modeling and using a custom-made metal augment.

AIM: To evaluate the results of reverse shoulder arthroplasty using the standard method and the use of an individual metal augment for deformities of the articular process of the scapula.

MATERIALS AND METHODS: In the period from 2019 to 2024, 62 patients with scapulohumeral arthrosis accompanied by deformation of the glenoid were treated in the Traumatology and Orthopedics Department No. 1 of the N.N. Priorov National Medical Research Center of Traumatology and Orthopedics (Moscow). Standard reverse shoulder arthroplasty was performed in 31 patients, and a custom-made metal augment manufactured using additive technologies was implanted in another 31 patients. Demographic data, radiographic data, surgical method, operative time, blood loss, and complications were taken into account. After the surgery, the patients were examined 6 weeks, 3 months, 6 months, and 1 year after the surgery. The functional outcome was assessed using the ASES, DASH, UCLA, Constant, and VAS scales.

RESULTS: Of the 62 patients, 19 (30.64%) were male and 43 (69.36%) were female. Glenoid deformity according to Walch: B1 — 31, B2 —19, B3 —12. The abduction angle was 120.6±6.9° at the first postoperative examination and 173.2±6.8° at the last one; before the operation it was 83.4±12.8° (p <0.05). In the group of patients with an individual augment, when compared with the control group, an increase in abduction, flexion and external rotation was noted after the operation, as well as a decrease in the time to the onset of a full range of motion in the shoulder joint.

CONCLUSION: Both methods resulted in similar improvements in functional outcomes. However, the augment method was associated with a higher rate of full shoulder range of motion, justifying further evaluation of this technique.